Here are 12 of the strangest self-declared, independent nations around the world, ranked by their estimated population size from largest to smallest.

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12. Liberland is situated on the west bank of the Danube river, between Croatia and Serbia. A border dispute between the two countries led Vít Jedlička to seize the "no man's land." The area was declared independent on 13 April, 2015. The Libertarian haven allows its nationals to set their own taxes, property, and individual rights. Population: 250,000.

11. The "Republica Glaciar" was declared an independent nation by Greenpeace activists in 2014. The environmental enthusiasts said that legal loopholes allowed them to claim the area located between Chile and Argentina. The nation, which has its own passports, aims to persuade South American governments to preserve water reserves. Population: 100,000.

10. The Republic of Užupis exists within a neighbourhood of Lithuania's capital Vilinius. On April Fools' Day in 1997, people living in the area declared it an independent nation. The Republic has its own politicians, currency, constitution, and even an army of around 12 soldiers. Population: 7,000.

9. Imperial Throne was founded in 2011 by Russian businessman Anton Bakov. The micronation which claims to be the successor to the historic Russian Empire has declared its ownership of 17 separate lands and islands. Population: 4,000.

Anton Bakov and Karl Emich of Leiningen sign the founding documents of State Imperial.Anton Bakov/Wikipedia

8. The Empire of Atlantium was founded by George Cruickshank (who calls himself Imperial Majesty George II) in 1981. Atlantium says it "offers an alternative to the discriminatory historic practice of assigning nationality to individuals on the basis of accidents of birth or circumstance." The self-declared nation lies 220 miles west of Sydney, Australia. Population: 3,000.

7. Freetown Christiania is probably one of the most legitimate independent territories in this ranking. The environmentally friendly commune in Copenhagen was established in 1971, and is now made up of houses, restaurants, art galleries, and music venues. The society has its own rules, independent of the Danish government. Population: 850.

6. Westarctica was founded by Travis McHenry in 2001, with the aim of bringing media attention to conservation issues in the small area formerly known as Marie Byrd Land. Population: 391.

5. The Principality of Seborga was historically an undisputed state. Over time, its status was forgotten, but local resident Giorgio Carbone resurfaced a claim for its independence in the 1960s. Seborga is situated in northwest Italy, and is in sight of a recognised independent sovereign state: Monaco. Population: 320.

4. The Republic of Molossia, located in northern Nevada has its own government, currency, postal service, and tourist attractions. It was founded in 1977 by resident Kevin Baugh for a joke, but it has now become much more serious. Population: 31.

3. Sealand — a fortress in the North Sea — was constructed by the British government during World War II. However, because it was built in international waters, once the fortress was abandoned it became an extra-national territory, according to the nation's official website. On December 24,1966, Roy Bates, a former soldier and "pirate" radio DJ claimed it as an independent country and christened it Sealand. Population: 27.

Watch Sealand's national anthem below:

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2. The Principality of Pontinha was founded by a schoolteacher from Madeira, Portugal, in 2007. The former fort, lying just off the coast of the island, is little more than a large rock. Nevertheless, its owner has declared himself Prince Renato II. He claims to have received threats from the Portuguese government. Population: 3.

1. The territory of Elgaland-Vargaland pushes the limits of nationhood even further. The independent "Digital Territory" defines itself as the borders of other countries. So, when you cross the border from one recognised country to another, you supposedly briefly enter Elgaland-Vargaland. The territory was invented by Swedish artists Carl Michael von Hausswolff and Leif Elggren in 1992. Population: 0.

Citizens of Elgaland-Vargaland at a summit of real and imaginary countries at New School University in Manhattan.
Joe Tabacca/AP Images